Home > Publications database > Spaltproduktfreisetzungsverlauf von Kugelbrennelementen bei Störfalltemperaturen |
Book/Report | FZJ-2016-05184 |
; ;
1986
Kernforschungsanlage Jülich GmbH, Zentralbiliothek, Verlag
Jülich
Please use a persistent id in citations: http://hdl.handle.net/2128/12483
Report No.: Juel-2091
Abstract: With the construction of the cold finger apparatus a new method has been developed to determine fission product release profiles during heating tests of irradiated spherical fuel elements. It is shown that this setup works with high sensitivity and high precision for all key nuclides up to 1800 °C. Together with the existing equipment, a total of 22 fuel elements with modern TRISO particles has been tested in the temperature range 1500 - 2500 °C. Additionally, release profiles of iodine and other isotopes have been obtained with seven UO$_{2}$ samples at 1400 - 1800 °C. For heating times up to 100 hours at the maximum temperature, the following results are pertinent to HTR accident conditions : Ag 110m is the only fission product to be released at 1200 - 1600 °C by diffusion through intact SiC, but it is of low significance in accident assessments ; cesium, iodine, strontium, and noble gas releases up to 1600 °C are solely due to various forms of contamination; at 1700 - 1800 °C, corrosion induced SiC defects cause the release of Cs, Sr, I/Xe/Kr; above 2000 °C, thermal decomposition of the silicon carbide layer sets in while pyrocarbons still remain intact. Around 1600 °C, the accident specific contribution of cesium, strontium, iodine, and noble gases is negligible.
The record appears in these collections: |